This 4 ingredient keto peanut butter fudge is a super satisfying treat. You assemble it in only 5 minutes and then simply cool it in the freezer. Rich, creamy and perfect for peanut butter fans! Low carb and sugar free.
I'm a big fan of easy treats. And I love having a stash of goodies in the freezer for those moments when you're craving a pick-me-up.
That's why I love fat bombs, and, by extension, keto fudge (which is essentially the same thing as a fat bomb).
My friends, you don't need a fancy piece of cake that takes 1 hour to bake - even though that CAN be a lot of fun when the time is right. A square of Keto fudge can hit the spot just as well!
This peanut butter fudge is extra creamy thanks to the peanut butter AND a generous portion of butter. Due to the high fat content, one 1.5 inch square is a rather satisfying portion.
Plus, I've added protein powder to give us a nice protein boost whilst it is doing its job firming up the fudge. It's a two-in-one win-win!
How to make keto peanut butter fudge:
1.) Get all your ingredients ready and melt the butter.
If your peanut butter doesn't contain salt, make sure you add some salt to the mix - it really improves the taste.
The vanilla extract is not essential, but if you have it in the house, definitely use it! The taste is even more intense if you have vanilla bean paste or vanilla powder.
2.) Stir all ingredients together with a fork.
3.) Line a 5x7 inch tray with parchment and pour in the mix. Spread out with a spatula.
Tip: My tray was actually larger than 5x7 inch. I simply used a scrunched up piece of aluminium foil and used it as a barrier underneath the parchment paper. This way, I managed to only use ⅔ of my tray without the fudge spreading.
4.) Freeze your fudge around 40 minutes until set.
Then run a sharp knife under hot water and cut it into 16 squares. This way you're getting perfect sides as the knife will glide through the fudge.
Keto Peanut butter fudge variations
You can make this fudge with any nut or seed butter. Almond butter would work well, and sunflower seed butter would be a good alternative too.
Chocolate fans can turn this fudge chocolatey by adding 2 tablespoon cocoa powder. (Alternatively, check out my Keto Chocolate Peanut Butter Fudge, which includes LOTS of melted chocolate - it's divine).
If you're using almond butter or a seed butter, 1 tablespoon of tahini would be an interesting flavour addition.
Note: I wouldn't recommend tahini for the peanut butter version though as I don't feel the two would gel.
You could also consider adding spices such as 1-2 teaspoon cinnamon or ½ teaspoon cardamom. If you're into autumnal flavours, 1-2 teaspoon of pumpkin spice (mixed spice in the UK) would jazz this fudge up even further.
Last but not least, if you don't have whey protein powder, you can replace it with any other unflavoured protein powder. The flavoured ones often contain sugars. Collagen protein powder also works well.
Alternatively, use 3 tablespoon of coconut flour to thicken the fudge instead of using protein powder. I used coconut flour in my Low Carb Peanut Butter Protein Bars, which worked well.
Tried this recipe? Give it a star rating below!
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Keto Peanut Butter Fudgefrom Sugar Free Londoner
Note: The servings slider only changes the first amount in each line and not any subsequent amounts. Please make your own calculations where necessary. ***As an Amazon Associate I earn from qualifying purchases.
- 1 cup / 260g peanut butter
- ⅓ cup / 60g butter unsalted
- ⅓ cup / 40g powdered sweetener
- ½ cup / 35g whey protein powder
- 1 teaspoon vanilla extract optional
- pinch of salt if your peanut butter is unsalted
- Melt the butter and stir all ingredients together with a fork.
- Line a 5x7 inch tray with parchment and pour in the mix.
- Freeze 40 minutes until set.
- Cut into 1.5 inch squares and enjoy! Store in the freezer.
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This recipe sounds delicious! To add a bit of chocolate to this, would it be better to stir in some Sugar Free chocolate chips before chilling, or pour some melted SF chocolate on top of it before chilling?
Either would work. However, the fudge is probably easier to eat if you stir in chocolate chips. That way, the chocolate can't break off when you bite into the fudge as it will set harder.
Found this and made it straight away! Was super easy to make and super yummy!
Hubby can't stop eating it (I think I will have to hide it haha)
Super easy to make and incredibly tasty!
I made these last night. Super easy and yummy! I think I'll also try drizzling or dipping some in some unsweetened chocolate, for a Reese's PB Cup style. Now to just keep from peeking in the freezer and grabbing one, lol!
Thanks for all your great recipes!
Delicious! Love it snd so easy .
This is an awesome recipe, and excellent even for beginners to the low-carb/keto lifestyle. Honestly, it's one of the lovely things that helped me to make it through the first month in transitioning away from sugar and wheat. I also later found that while it is still soft, you can pipe it like frosting. I put some in a freezer zip-loc bag, but the tip, and used it as frosing to make peanut butter sandwich cookies.
What a great recipe Katrin, so simple, so quick.and so delicious .Thank you for all your hard work. We love your recipes here in Sydney.
So glad you all like the fudge!
Before, I would dig a tablespoon to a jar of Whole Earth PB... and dig in again. Not good when you're counting calories.
Made this yesterday for the first time and already I'm loving the fact that I can just restrict myself to a single square as an earned treat.
Melts in your mouth, too - just perfect with an afternoon cup of tea.
Cannot thank you enough for this recipe. Not the first of yours to make us swoon! I keep this on hand continuously and we enjoy slivers of it as our secret treat whenever. Absolute delight!
What an amazing recipe. I made this last night and my family loved it. Thank you for all of your fantastic recipes
Thank you sooo much for this recipe. I enjoyed it imensily and so did my daughters.
I haven't tried anything new in a while. This one did the trick.
It brought me out of my depression very nicely.
Be healthy and safe with your family.
Lots of Love
Fani and daughters
I'm glad it cheered you up! Have a wonderful weekend 🙂
Hi. Can I use collagen peptides in place of the whey protein powder or is that a totally different animal?
Hi, I haven't tried it but my guess is that it would probably work just as well.
We love this recipe. This has been a lifesaver in staying with keto, especially for my husband. I have played with it some, at times I'll add cinnamon, and my husband's favorite is chocolate. I'll put a layer of my keto chocolate, chill, this fudge, chill and finish with another layer of chocolate and chill again. I make it in silicone muffin cups and Vance thinks it's better than Reece's cups. Too sweet for me but a special treat for him. Thanks so much for yhis and all of your recipes.
That sounds AMAZING!!!!!!
While I did not specifically note this in the recipe, I would recommend that unsalted/natural peanut butter be used. I used regular peanut butter and the mixture was excessively salty. Perhaps it would have been less salty had I also not used salted butter! Also, I would not recommend using sweetener containing saccharin. The 1/3 cup of sweetener I used left an unpleasant aftertaste. I tried using erythritol (Swerve) which provided a much better result. As with many recipes, I suspect we learn through trial and error!
Thanks for your comment Susan! I always use unsalted peanut butter AND unsalted butter. I'll include that in the recipe description!
Please try Lakanto monk fruit in your recipes it’s fabulous!!!
Do you mean the pure monk fruit or the erythritol blend? I use the blend all the time.
I used almond flour in place of the whey protein powder for less carb content. It mixed up well. It is currently in the freezer. I think it will do well
Yes, that should work well, I agree. Let me know here how they turned out?
Just came across your website as I start my keto regime during Covid-19 lock down - and boy am I glad I came across it.
Your recipes look amazing!
Have been reading about the virtues of fat bombs so thought his recipe would be a good intro.
Only thing is, I don't have any whey powder (unless Slimfast milkshake powder would work?).
What else could I use, or can I omit it from the recipe?
If you have some coconut flour that would make a good alternative. But my guess is to use less as it's absorbent!
How much coconut flour would you recommend?
Depending on how firm or runny your peanut butter is, I would start with 2-3 tbsp.
This was super easy to make!
I did make some changes just because of what was available, but it was delicious just the same!
I used vanilla whey protein (it's what I could find and already had a small amount of sweetener in it) and omitted the powdered sweetener. I also added the vanilla extract, though the next time I make this, I will omit it if using vanilla whey as the flavor was slightly overpowering for my taste.
I rarely find recipes that I truly enjoy, but this was definitely one of them! Thank you so much! I love your blog! Keep up the great work!
Glad it hit the spot!
Unbelievably yummy! I love your recipes, but I think this one qualifies as my new favourite.
Many thanks for providing such delicious free recipes. I really appreciate the metric weights and measures, especially for solid fats.
The peanut butter I used has nothing but peanuts & sea salt. Carbs are 2 per T.
Also put saran wrap in a loaf pan. When it was frozen, I cut it into 16 pcs, but mine are much bigger than 1.5" square, but I'm thinking it averages out about the same. Maybe mine aren't as thick as yours.
Very good recipe.
Glad you liked it!
Hi, I love your recipes, however when I pull them into my Carb Tracker, the net carbs / carbs never work out the same as you have calculated - e.g. for this recipe the net carbs come out at around 2g - I've checked all the ingredients and amended them where needed - but they still always seem to come out as a lot more 🙁
Hi Kelly, I used the Meridian peanut butter in this recipe (which uses only peanuts and nothing else). I used the ketodiet app nutrition calculator to calculate the macros for this recipe. And I did notice they have other peanut butter brands on it which have a higher carb count. Different products will always have different nutritional profiles. Maybe that's where the calculators differ.
I'm not a big fan of peanut butter. How do I modify it to make chocolate?
Hi Janie, you'd have to change this recipe quite a lot as the main ingredient is peanut butter. If you do dairy, I'd make chocolate fudge with good quality melted chocolate, sweetener and butter (maybe some cacao butter). If you're dairy free, you can use coconut oil in place of the butter. I'd make sure the butter/coconut oil are NOT melted, but room temperature instead so the sweetener does not sink to the bottom.
Just made the recipe and the fudge is yummy. There was one drawback though. The erythritol and stevia sweetener I used wasn’t fine enough to fully dissolve in the mixture and so when eating there are some detectable small crunchy granules of sweetener. So if one is using a sweetener which isn’t a super fine power, then I would suggest adding it to the melted butter and letting it fully dissolve before mixing in the other ingredients.
sounds like you used granulated sweetener and not powdered. You can easily powder it at home by blending it in a food processor or with a stick blender that has an attachment. If you haven't got either, melting it in the butter is a great idea 🙂
Thanks. I’ll remember to do that next time I make the recipe. Planning to make the peanut butter chocolate fudge next.
Hi! Is there any substitute for the powdered sweetener? Don't have it in the house and trying to see if I can still make these. Thanks!
Liquid stevia would also work. Or any sugar free syrup.
This Keto peanut butter fudge is a really excellent idea, so easy to prepare and so quickly ready to enjoy. The squares constituted a welcomed recompense for my children working that hard at home these difficult times.
As you recommended I added some vanilla extract to the mass, as vanilla is my absolute favorite flavour and also a tsp of cinnamon. We all loved it.
As the kids will have to go on studying at home, they really deserve some extra treat. Tomorrow I'll surprise them with a chocolate variation of this recipe.
One of my most appreciated criteria of your always original ideas is that your recipes can be used as basic offer, and everyone can modify or upgrade them, due to his personal liking or the content of the fridge and the pantry.
Special thanks for the idea of running the knife under hot water before cutting the fudge in cubes. It worked perfect.
Awaiting with pleasure further culinary creations, Ruth
Hi Ruth, I'm so glad you like the recipe. Next time I make it I will drizzle some melted 90% chocolate over the mix. So, if you should make this recipe again, there's another idea for you 😉
That’s lovely, thank you so much. I'm looking forward to this.
I had to make it s soon as I read the recipe, just in time to serve after dinner. We love your recipes!
Wonderful! So glad it hit the spot!
I love your recipes but the ads drive me mad forever appearing! Is there a better way to view your stuff x
Hi Linda, I'm so sorry the ads bother you. Unfortunately I cannot afford to turn them off this is how my blog earns money (it's my full time job and I depend on it). There is a jump to recipe button at the top of each post and you can also print the recipes. I hope this helps and you can find a way to ignore the ads. Have a great day 🙂
Katrin, your recipes are the best and always full of heart. This fudge is great! I've even used coconut butter successfully.
I know ads are how you are able to share your talents and gifts with all of us so I just thank God every time one comes along because I know it's how I keep benefiting
Blessings upon you and yours as we move into springtime in Texas!
Hi Laney, thanks for your kind words! And I'm really happy you're enjoying the fudge!